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Muva nje, kuthuthukiswe ipulatifomu engenamakhemikhali yokulwa namagciwane esekelwe kubuchwepheshe be-nanotechnology esebenzisa izakhiwo zamanzi ezenziwe ngokwenziwa (i-EWNS). I-EWNS ine-charge ephezulu ebusweni futhi icebile ngezinhlobo ze-oxygen ezisebenzayo (i-ROS) ezingasebenzisana futhi zivimbele inani lamagciwane, okuhlanganisa nezifo ezitholakala ekudleni. Lapha kuboniswa ukuthi izakhiwo zazo ngesikhathi sokwenziwa zingalungiswa kahle futhi zilungiselelwe ukuthuthukisa amandla azo okulwa namagciwane. Ipulatifomu yelabhorethri ye-EWNS yaklanywa ukuze ilungise izakhiwo ze-EWNS ngokushintsha amapharamitha okwenziwa. Ukucaciswa kwezakhiwo ze-EWNS (i-charge, usayizi, kanye nokuqukethwe kwe-ROS) kwenziwa kusetshenziswa izindlela zesimanje zokuhlaziya. Ngaphezu kwalokho, amagciwane okudla afana ne-Escherichia coli, i-Salmonella enterica, i-Listeria innocua, i-Mycobacterium para fortitum, kanye ne-Saccharomyces cerevisiae afakwe umjovo ebusweni botamatisi bamagilebhisi bemvelo ukuze kuhlolwe amandla awo okungasebenzi kwamagciwane. Imiphumela evezwe lapha ikhombisa ukuthi izakhiwo ze-EWNS zingalungiswa kahle ngesikhathi sokwenziwa, okuholela ekwandeni okukhulu kokusebenza kahle kokungasebenzi. Ikakhulukazi, ishaja engaphezulu yanda ngesilinganiso sesine, kanti okuqukethwe yi-ROS kwanda. Izinga lokususwa kwamagciwane lalincike kumagciwane futhi lalisukela ku-1.0 kuya ku-3.8 log ngemva kwemizuzu engu-45 yokuchayeka kumthamo we-aerosol ongu-40,000 #/cm3 EWNS.
Ukungcola kwamagciwane kuyimbangela eyinhloko yezifo ezibangelwa ukudla okubangelwa ukugwinya amagciwane noma ubuthi bawo. Ukugula okubangelwa ukudla kubangela izifo ezingaba yizigidi ezingu-76, ukulaliswa esibhedlela okungu-325,000, kanye nokufa okungu-5,000 minyaka yonke e-United States kuphela1. Ngaphezu kwalokho, uMnyango Wezolimo wase-United States (i-USDA) ulinganisela ukuthi ukusetshenziswa okwengeziwe kwemikhiqizo emisha kubangelwa amaphesenti angu-48 azo zonke izifo ezibangelwa ukudla ezibikiwe e-United States2. Izindleko zokugula nokufa ezibangelwa amagciwane abangelwa ukudla e-United States ziphakeme kakhulu, kulinganiselwa yi-Centers for Disease Control and Prevention (CDC) ukuthi zingaphezu kuka-US$15.6 billion ngonyaka3.
Njengamanje, ukungenelela kwamakhemikhali, imisebe5 kanye namagciwane okushisa6 ukuqinisekisa ukuphepha kokudla kusetshenziswa kakhulu ezindaweni zokulawula ezibalulekile ezinqunyelwe (ama-CCP) ochungechungeni lokukhiqiza (ngokuvamile ngemva kokuvuna kanye/noma ngesikhathi sokupakisha) kunokuba kusetshenziswe ngokuqhubekayo ngendlela yokuthi umkhiqizo omusha ungcoliswe ngokuphambeneyo 7. Ukungenelela kwamagciwane kuyadingeka ukulawula kangcono izifo ezibangelwa ukudla kanye nokonakala kokudla futhi kunamandla okusetshenziswa kuyo yonke inkathi yepulazi netafula. Umthelela omncane kanye nezindleko ezincane.
Muva nje kuthuthukiswe ipulatifomu yama-antimicrobial esekwe ku-nanotechnology ukuze kuvinjwe amabhaktheriya ezindaweni nasemoyeni kusetshenziswa izakhiwo zamanzi ezenziwe ngokwenziwa (i-EWNS). Ekuhlanganisweni kwe-EVNS, kusetshenziswe izinqubo ezimbili ezifanayo: i-electrospray kanye ne-ionization yamanzi (Isithombe 1a). Ama-EWNS aboniswe ngaphambilini ukuthi anesethi ehlukile yezakhiwo zomzimba nezebhayoloji8,9,10. I-EWNS inesilinganiso sama-electron ayi-10 ngesakhiwo ngasinye kanye nosayizi we-nanometer ojwayelekile ongu-25 nm (Isithombe 1b,c)8,9,10. Ngaphezu kwalokho, i-electron spin resonance (ESR) ikhombisile ukuthi ama-EWNS aqukethe inani elikhulu lezinhlobo ze-oxygen ezisebenzayo (i-ROS), ikakhulukazi i-hydroxyl (OH•) kanye ne-superoxide (O2-) radicals (Isithombe 1c)8. Ama-EWNS ahlala emoyeni isikhathi eside futhi angashayisana nama-microbes amiswe emoyeni futhi abe khona ezindaweni, alethe umthwalo wawo we-ROS futhi abangele ukungasebenzi kwama-microbial (Isithombe 1d). Lezi zifundo zangaphambilini zikhombisile nokuthi i-EWNS ingasebenzisana futhi ivimbele amagciwane ahlukahlukene angenayo i-gram kanye ne-gram abalulekile empilweni yomphakathi, kufaka phakathi i-mycobacteria, ezindaweni nasemoyeni8,9. I-transmission electron microscopy ibonise ukuthi ukungasebenzi kwabangelwa ukuphazamiseka kwe-membrane yeseli. Ngaphezu kwalokho, izifundo zokuphefumula ngokushesha zikhombisile ukuthi imithamo ephezulu ye-EWNS ayibangeli ukulimala kwamaphaphu noma ukuvuvukala8.
(a) I-Electrospray yenzeka lapho kusetshenziswa i-voltage ephezulu phakathi kwe-capillary equkethe uketshezi kanye ne-counter electrode. (b) Ukusetshenziswa kwe-voltage ephezulu kuphumela ezimweni ezimbili ezihlukene: (i) ukufutha amanzi nge-electrode kanye (ii) ukukhiqizwa kwezinhlobo ze-oxygen (ama-ion) ezibambeke ku-EWNS. (c) Isakhiwo esiyingqayizivele se-EWNS. (d) Ama-EWNS ahamba kakhulu ngenxa yemvelo yawo encane futhi angasebenzisana nezifo ezibangelwa amagciwane emoyeni.
Ikhono leplatifomu ye-EWNS yokulwa namagciwane lokumisa amagciwane atholakala ekudleni ebusweni bokudla okusha nalo liboniswe muva nje. Kuye kwaboniswa nokuthi ishaja lobuso le-EWNS lingasetshenziswa lihlanganiswe nensimu kagesi ukuze kuthunyelwe okuqondiwe. Okubaluleke kakhulu, umphumela wokuqala othembisayo wokunciphisa cishe ama-log angu-1.4 emsebenzini katamatisi wemvelo ngokumelene namagciwane ahlukahlukene okudla njenge-E. coli ne-Listeria wabonwa zingakapheli imizuzu engama-90 yokuchayeka ku-EWNS ekugxilweni okungaba ngu-50,000#/cm311. Ngaphezu kwalokho, ukuhlolwa kokuqala kokuhlolwa kwe-organoleptic akubonisanga mphumela we-organoleptic uma kuqhathaniswa notamatisi wokulawula. Nakuba le miphumela yokuqala yokungasebenzi ithembisa ukuphepha kokudla ngisho nasemithini ephansi kakhulu ye-EWNS engu-50,000#/cc. bheka, kusobala ukuthi amandla aphezulu okungasebenzi angaba wusizo kakhulu ekunciphiseni ingozi yokutheleleka kanye nokonakala.
Lapha, sizogxila ocwaningweni lwethu ekuthuthukisweni kwepulatifomu yokukhiqiza i-EWNS ukuze kulungiswe kahle amapharamitha okwenziwa futhi kuthuthukiswe izakhiwo ze-physicochemical ze-EWNS ukuze kuthuthukiswe amandla azo okulwa namagciwane. Ikakhulukazi, ukwenza ngcono kugxile ekwandiseni ukushaja kwendawo yazo (ukuthuthukisa ukulethwa okuqondiwe) kanye nokuqukethwe kwe-ROS (ukuthuthukisa ukusebenza kahle kokungasebenzi). Ukuchazwa kwezakhiwo ze-physico-chemical ezilungiselelwe (usayizi, ukushaja kanye nokuqukethwe kwe-ROS) kusetshenziswa izindlela zesimanje zokuhlaziya kanye nokusebenzisa izinto ezincane zokudla ezivamile njenge-E. coli, i-S. enterica, i-L. innocua, i-S. cerevisiae kanye ne-M. parafortuitum.
I-EVNS yakhiwe ngokufafaza ngogesi kanyekanye kanye nokufaka amanzi ahlanzekile aphezulu (18 MΩ cm–1). I-atomizer kagesi 12 ivame ukusetshenziselwa ukwenza i-atomize uketshezi kanye ne-polymer yokwenziwa kanye nezinhlayiya ze-ceramic 13 kanye nemicu 14 yobukhulu obulawulwayo.
Njengoba kuchaziwe ezincwadini zangaphambilini 8, 9, 10, 11, ekuhlolweni okuvamile, kusetshenziswa i-voltage ephezulu phakathi kwe-capillary yensimbi kanye ne-counter electrode egxilile. Phakathi nale nqubo, kwenzeka izenzakalo ezimbili ezahlukene: 1) i-electrospray kanye ne-2) i-ionization yamanzi. Insimu kagesi enamandla phakathi kwama-electrode amabili ibangela ukuthi kube nokushaja okungekuhle ebusweni bamanzi ahlanganisiwe, okuholela ekwakhekeni kwama-cone e-Taylor. Ngenxa yalokho, kwakheka amaconsi amanzi ashajwe kakhulu, aqhubeka nokuqhekeka abe yizinhlayiya ezincane, ngokusho kwe-Rayleigh theory16. Ngesikhathi esifanayo, insimu kagesi enamandla ibangela ukuthi amanye ama-molecule amanzi ahlukane futhi asuse ama-electron (ionization), ngaleyo ndlela akhiqize inani elikhulu lezinhlobo ze-oxygen ezisebenzayo (ROS)17. Amaphakethe e-ROS18 akhiqizwe ngasikhathi sinye afakwe ku-EWNS (Isithombe 1c).
Kumfanekiso 2a kukhombisa uhlelo lokukhiqiza i-EWNS olwakhiwe futhi lwasetshenziswa ekuhlanganisweni kwe-EWNS kulolu cwaningo. Amanzi ahlanziwe agcinwe ebhodleleni elivaliwe afakwa ngethubhu le-Teflon (ububanzi bangaphakathi obungu-2 mm) enalenithi yensimbi engagqwali engu-30G (i-capillary yensimbi). Njengoba kuboniswe kuMfanekiso 2b, ukugeleza kwamanzi kulawulwa umfutho womoya ngaphakathi ebhodleleni. Inalithi ixhunywe kukhonsoli ye-Teflon engalungiswa ngesandla ibanga elithile ukusuka ku-electrode yekhawunta. I-electrode yekhawunta iyidiski ye-aluminium epholishiwe enembobo phakathi ukuze kuthathwe isampula. Ngaphansi kwe-electrode yekhawunta kukhona i-funnel yesampula ye-aluminium, exhunywe kokunye ukusethwa kokuhlola nge-port yesampula (Umfanekiso 2b). Zonke izingxenye zesampula zisekelwe ngogesi ukuze kugwenywe ukwakheka kweshaja okungalimaza ukusampula kwezinhlayiya.
(a) Uhlelo Lokukhiqiza Isakhiwo Samanzi Esinobunjiniyela (i-EWNS). (b) Ingxenye enqamulayo yeyunithi yesampula kanye ne-electrospray ekhombisa amapharamitha abaluleke kakhulu. (c) Ukusethwa kokuhlola kokungasebenzi kwamagciwane.
Uhlelo lokukhiqiza i-EWNS oluchazwe ngenhla luyakwazi ukushintsha amapharamitha okusebenza abalulekile ukuze kube lula ukulungisa kahle izakhiwo ze-EWNS. Lungisa i-voltage esetshenzisiwe (V), ibanga eliphakathi kwenaliti ne-counter electrode (L), kanye nokugeleza kwamanzi (φ) nge-capillary ukuze kulungiswe kahle izici ze-EWNS. Izimpawu [V (kV), L (cm)] zisetshenziselwa ukubonisa inhlanganisela ehlukene. Lungisa ukugeleza kwamanzi ukuze uthole ikhoni ye-Taylor ezinzile yesethi ethile [V, L]. Ngenhloso yalolu cwaningo, ukuvuleka kwe-counter electrode (D) kwasethwa ku-0.5 inches (1.29 cm).
Ngenxa ye-geometry elinganiselwe kanye ne-asymmetry, amandla ensimu kagesi awakwazi ukubalwa kusukela ezimisweni zokuqala. Esikhundleni salokho, isofthiwe ye-QuickField™ (Svendborg, Denmark)19 yasetshenziswa ukubala insimu kagesi. Insimu kagesi ayifani, ngakho-ke inani lensimu kagesi esiqongweni se-capillary lasetshenziswa njengenani lokubhekisela ekucushweni okuhlukahlukene.
Ngesikhathi socwaningo, kwahlolwa inhlanganisela eziningana ze-voltage kanye nebanga phakathi kwenaliti kanye ne-counter electrode ngokuya ngokwakheka kwe-Taylor cone, ukuzinza kwe-Taylor cone, ukuzinza kokukhiqizwa kwe-EWNS, kanye nokuphindaphinda. Inhlanganisela ehlukahlukene iboniswe kuThebula Elingeziwe S1.
Umphumela wohlelo lokukhiqiza i-EWNS uxhunywe ngqo ku-Scanning Mobility Particle Sizer (SMPS, imodeli 3936, TSI, Shoreview, Minnesota) ukukala ukuhlushwa kwenombolo yezinhlayiya futhi wasetshenziswa ne-Faraday aerosol electrometer (TSI, imodeli 3068B, Shoreview, USA). MN) ukukala ukugeleza kwe-aerosol, njengoba kuchaziwe encwadini yethu yangaphambilini9. Kokubili i-SMPS kanye ne-aerosol electrometer kuthathwe amasampula ngesilinganiso sokugeleza esingu-0.5 L/min (ukugeleza kwesampula okuphelele okungu-1 L/min). Ukuhlushwa kwezinhlayiya kanye nokugeleza kwe-aerosol kwalinganiswa imizuzwana engu-120. Phinda ukulinganisa izikhathi ezingu-30. Isamba se-aerosol charge sibalwa kusukela ekulinganisweni kwamanje, kanti isilinganiso se-EWNS charge silinganiswa kusukela enanini lonke lezinhlayiya ze-EWNS ezithathwe amasampula. Izindleko ezimaphakathi ze-EWNS zingabalwa kusetshenziswa i-Equation (1):
lapho i-IEl ingumshini olinganisiwe, i-NSMPS ingukuhlushwa kwenombolo okulinganiswe nge-SMPS, kanti i-φEl iyisilinganiso sokugeleza kuya ku-electrometer.
Ngenxa yokuthi umswakama ohlobene (RH) uthinta ukushaja kobuso, izinga lokushisa kanye (RH) kwagcinwa kungaguquki ku-21°C kanye no-45%, ngokulandelana, ngesikhathi sokuhlolwa.
I-Atomic force microscopy (AFM), i-Asylum MFP-3D (Asylum Research, Santa Barbara, CA) kanye ne-AC260T probe (Olympus, Tokyo, Japan) zasetshenziswa ukukala usayizi kanye nesikhathi sokuphila kwe-EWNS. Izinga lokuskena le-AFM lingu-1 Hz kanti indawo yokuskena ingu-5 µm×5 µm enemigqa yokuskena engu-256. Zonke izithombe zibekwe ekulinganisweni kwesithombe sokuqala kusetshenziswa isofthiwe ye-Asylum (imaski enobubanzi obungu-100 nm kanye nomkhawulo ongu-100 pm).
Susa i-sampling funnel bese ubeka ubuso be-mica ebangeni elingama-2.0 cm ukusuka ku-counter electrode isikhathi esimaphakathi samasekhondi angu-120 ukuze ugweme ukuhlangana kwezinhlayiya kanye nokwakheka kwamaconsi angajwayelekile ebusweni be-mica. I-EWNS yafakwa ngqo ezindaweni ze-mica ezisanda kusikwa (Ted Pella, Redding, CA). Ngokushesha ngemva kokukhafula, ubuso be-mica babonakala kusetshenziswa i-AFM. I-engeli yokuxhumana kobuso be-mica esanda kusikwa engakashintshwa iseduze no-0°, ngakho-ke i-EWNS isakazeka phezu kobuso be-mica ngesimo se-domed20. Ububanzi (a) kanye nokuphakama (h) kwamaconsi asakazekayo kwalinganiswa ngqo kusuka ku-topography ye-AFM futhi kwasetshenziswa ukubala ivolumu yokusabalala kwe-domed EWNS kusetshenziswa indlela yethu eqinisekisiwe ngaphambilini8. Uma sicabanga ukuthi i-EVNS esebhodini inomthamo ofanayo, ububanzi obufanayo bungabalwa kusuka ku-equation (2):
Ngokuhambisana nendlela yethu ethuthukisiwe ngaphambilini, kwasetshenziswa isicupho sokujikeleza se-electron spin resonance (ESR) ukuthola ukuthi kukhona ama-radical intermediates ahlala isikhathi esifushane ku-EWNS. Ama-aerosol adluliswa ngesisombululo esiqukethe i-235 mM DEPMPO (5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide) (Oxis International Inc., Portland, Oregon). Zonke izilinganiso ze-EPR zenziwa kusetshenziswa i-Bruker EMX spectrometer (Bruker Instruments Inc. Billerica, MA, USA) kanye nama-flat cell arrays. Isofthiwe ye-Acquisit (Bruker Instruments Inc. Billerica, MA, USA) yasetshenziswa ukuqoqa nokuhlaziya idatha. Ukuchazisisa kwe-ROS kwenziwa kuphela kusethi yezimo zokusebenza [-6.5 kV, 4.0 cm]. Ukuhlushwa kwe-EWNS kwalinganiswa kusetshenziswa i-SMPS ngemuva kokubheka ukulahlekelwa kwe-EWNS ku-impactor.
Amazinga e-Ozone aqashwe kusetshenziswa i-205 Dual Beam Ozone Monitor™ (2B Technologies, Boulder, Co)8,9,10.
Kuzo zonke izakhiwo ze-EWNS, inani lokulinganisa liyisilinganiso sezilinganiso, kanti iphutha lokulinganisa liwukuphambuka okujwayelekile. Kwenziwe ukuhlolwa kwe-t ukuze kuqhathaniswe inani lesici se-EWNS esilungisiwe nenani elihambisanayo le-base EWNS.
Isithombe 2c sibonisa i-Electrostatic Precipitation Pass Through System (EPES) eyake yathuthukiswa futhi yachazwa ngaphambilini engasetshenziswa ukukhomba i-EWNS11 ezindaweni. I-EPES isebenzisa ishaja ye-EWNS kanye nensimu kagesi enamandla ukuze "ikhombe" ngqo ebusweni bomhloli. Imininingwane yohlelo lwe-EPES ivezwe encwadini yakamuva kaPyrgiotakis et al.11. Ngakho-ke, i-EPES inekamelo le-PVC eliphrintiwe nge-3D elineziphetho ezinciphile eziqukethe amapuleti amabili ensimbi engagqwali ahambisanayo (insimbi engagqwali engu-304, epholishiwe ngesibuko) phakathi nendawo engama-15.24 cm. Amabhodi axhunywe emthonjeni wangaphandle we-voltage ephezulu (Bertran 205B-10R, Spellman, Hauppauge, NY), ibhodi elingezansi lalihlala lihle futhi ibhodi eliphezulu lalihlala liphansi (lintanta). Izindonga zegumbi zimbozwe nge-foil ye-aluminium, ephansi ngogesi ukuvimbela ukulahleka kwezinhlayiya. Ikamelo linomnyango wokulayisha ovaliwe ovumela izindawo zokuhlola ukuthi zibekwe kuma-rack epulasitiki, ziwaphakamise epuletini lensimbi elingezansi ukuze kugwenywe ukuphazamiseka kwe-voltage ephezulu.
Ukusebenza kahle kokufakwa kwe-EWNS ku-EPES kubalwe ngokwephrothokholi eyathuthukiswa ngaphambilini echazwe ku-Supplementary Figure S111.
Njengegumbi lokulawula, ukugeleza kwesibili ekamelweni eliyindilinga kuxhunywe ngokulandelana nohlelo lwe-EPES kusetshenziswa isihlungi se-HEPA esiphakathi ukususa i-EWNS. Njengoba kuboniswe ku-Fig. 2c, i-aerosol ye-EWNS yapontshwa ngamakamelo amabili axhunywe ngokulandelana. Isihlungi esiphakathi kwegumbi lokulawula ne-EPES sisusa noma yimaphi ama-EWNS asele okuholela ekushiseni okufanayo (T), umswakama ohlobene (RH) kanye namazinga e-ozone.
Kutholakale ukuthi ama-microorganisms abalulekile atholakala ekudleni angcolisa imikhiqizo emisha efana ne-Escherichia coli (ATCC #27325), inkomba yendle, i-Salmonella enterica (ATCC #53647), i-pathogen etholakala ekudleni, i-Listeria innocua (ATCC #33090), enye indlela esikhundleni se-Listeria monocytogenes. , i-Saccharomyces cerevisiae (ATCC #4098) njengendlela ehlukile esikhundleni semvubelo ebolile, kanye ne-Mycobacterium parafortuitous (ATCC #19686) njengebhaktheriya ephilayo emelana kakhulu yathengwa ku-ATCC (Manassas, Virginia).
Thenga amabhokisi katamatisi wamagilebhisi angahleliwe emakethe yangakini bese uwabeka efrijini ku-4°C kuze kube yilapho esetshenziswa (kufika ezinsukwini ezi-3). Khetha utamatisi ukuze uzame ngosayizi owodwa, cishe ububanzi obuyi-1/2 intshi.
Izindlela zokufaka utamatisi, ukugoma, ukuvezwa kanye nokubalwa kwekoloni zichazwe kabanzi ezincwadini zethu zangaphambilini futhi zachazwa ngokuningiliziwe ku-Supplementary Data 11. Ukusebenza kwe-EWNS kuhlolwe ngokubeka utamatisi ogomayo ku-40,000 #/cm3 imizuzu engama-45. Kafushane, ngesikhathi u-t = 0 min, kwasetshenziswa utamatisi abathathu ukuhlola amagciwane asindayo. Utamatisi abathathu bafakwa ku-EPES futhi bavezwa ku-EWNS ku-40,000 #/cc (utamatisi ovezwe yi-EWNS) kanti abanye abathathu bafakwa ekamelweni lokulawula (utamatisi wokulawula). Akukho neyodwa yamaqembu katamatisi eyacutshungulwa okwengeziwe. Utamatisi ovezwe yi-EWNS kanye nezilawuli zasuswa ngemva kwemizuzu engama-45 ukuhlola umphumela we-EWNS.
Ukuhlolwa ngakunye kwenziwa kathathu. Ukuhlaziywa kwedatha kwenziwa ngokwephrothokholi echazwe kuDatha Engeziwe.
Amasampula ebhaktheriya i-E. coli, i-Enterobacter, kanye ne-L. innocua adalulwe ku-EWNS (imizuzu engama-45, ukuhlushwa kwe-aerosol ye-EWNS okungu-40,000 #/cm3) kanye nalawo angakabonakali ahlanjululwe ukuze kuhlolwe izindlela zokungasebenzi. Ukuchayeka kwaqiniswa amahora ama-2 ekushiseni kwegumbi kusisombululo se-sodium cacodylate esingu-0.1 M (pH 7.4) nge-fixative engu-2.5% glutaraldehyde, i-1.25% paraformaldehyde kanye ne-0.03% picric acid. Ngemva kokuwasha, aqiniswa nge-1% osmium tetroxide (OsO4)/1.5% potassium ferrocyanide (KFeCN6) amahora ama-2, agezwa izikhathi ezi-3 ngamanzi futhi afakwe ku-1% uranyl acetate ihora eli-1, bese egezwa kabili ngamanzi. Ukuphelelwa amanzi emzimbeni okulandelayo kuthathe imizuzu eyi-10 ngayinye ye-50%, 70%, 90%, 100% alcohol. Amasampula abe esefakwa ku-propylene oxide ihora eli-1 bese efakwa ingxube ye-propylene oxide engu-1:1 kanye ne-TAAP Epon (Marivac Canada Inc. St. Laurent, CA). Amasampula afakwa ku-TAAB Epon futhi afakwa i-polymer ku-60°C amahora angu-48. I-resin ehlanganisiwe elungisiwe yasikwa futhi yabonwa yi-TEM kusetshenziswa i-JEOL 1200EX (JEOL, Tokyo, Japan), i-microscope evamile yokudlulisa i-electron efakwe ikhamera ye-AMT 2k CCD (Advanced Microscopy Techniques, Corp., Woburn, MA, USA).
Zonke izivivinyo zenziwe kathathu. Ngesikhathi ngasinye, ukugeza kwamagciwane kwafakwa amapuleti kathathu, okwaholela ekutheni kube namaphuzu edatha ayisishiyagalolunye ngephuzu ngalinye, isilinganiso sawo sasetshenziswa njengokuhlushwa kwamagciwane kwaleyo nto ethile. Ukuphambuka okujwayelekile kwasetshenziswa njengephutha lokulinganisa. Wonke amaphuzu abalwa.
I-logarithm yokwehla kokuhlushwa kwamagciwane uma kuqhathaniswa ne-t = 0 min ibalwa kusetshenziswa ifomula elandelayo:
lapho i-C0 ingukuhlushwa kwamabhaktheriya kusampula yokulawula ngesikhathi esingu-0 (okungukuthi ngemva kokuba ubuso bomile kodwa ngaphambi kokufakwa ekamelweni) kanye ne-Cn ingukuhlushwa kwamabhaktheriya ebusweni ngemva kwemizuzu engu-n yokuchayeka.
Ukuze kucatshangelwe ukuwohloka kwemvelo kwamagciwane phakathi nesikhathi sokuchayeka semizuzu engama-45, i-Log-Reduction nayo yabalwa uma kuqhathaniswa nokulawula ngemizuzu engama-45 kanje:
Lapho i-Cn ingukuhlushwa kwamagciwane kusampula yokulawula ngesikhathi i-n kanye ne-Cn-Control ingukuhlushwa kwamagciwane okulawula ngesikhathi i-n. Idatha yethulwa njengokunciphisa kwelogi uma kuqhathaniswa nokulawula (akukho ukuvezwa kwe-EWNS).
Ngesikhathi socwaningo, inhlanganisela eziningana ze-voltage kanye nebanga phakathi kwenaliti kanye ne-counter electrode yahlolwa ngokuya ngokwakheka kwe-Taylor cone, ukuzinza kwe-Taylor cone, ukuzinza kokukhiqizwa kwe-EWNS, kanye nokuphindeka. Inhlanganisela ehlukahlukene iboniswe kuThebula Elingeziwe S1. Amacala amabili akhethiwe ocwaningweni oluphelele olubonisa izakhiwo ezizinzile neziphindeka kabusha (i-Taylor cone, ukukhiqizwa kwe-EWNS, kanye nokuzinza ngokuhamba kwesikhathi). Ku-Fig. 3 kukhombisa imiphumela yokushaja, usayizi kanye nokuqukethwe kwe-ROS yamacala amabili. Imiphumela iphinde ifingqwe kuThebula 1. Ukuze kubhekwe, iSithombe 3 kanye neThebula 1 zifaka izakhiwo ze-EWNS8, 9, 10, 11 ezingazange zilungiselelwe ngaphambilini (baseline-EWNS). Izibalo zokubaluleka kwezibalo ezisebenzisa i-t-test enemisila emibili ziphinde zanyatheliswa kuThebula Elingeziwe S2. Ngaphezu kwalokho, idatha eyengeziwe ifaka izifundo ngomphumela we-counter electrode sampling hole diameter (D) kanye nebanga phakathi kwe-ground electrode kanye nesihloko senalithi (L) (Izibalo Ezingeziwe S2 kanye ne-S3).
(a–c) Ukusatshalaliswa kosayizi we-AFM. (d – f) Isici seshaja engaphezulu. (g) Ukuchazwa kwe-ROS ne-ESR.
Kubalulekile futhi ukuqaphela ukuthi kuzo zonke izimo ezingenhla, ama-current ionization alinganisiwe ayephakathi kuka-2-6 µA, kanti ama-voltage ayephakathi kuka--3.8 kuya ku--6.5 kV, okwaholela ekusetshenzisweni kwamandla kwale EWNS eyodwa engaphansi kuka-50 mW. . module yokukhiqiza. Nakuba i-EWNS yenziwe ngaphansi kokucindezela okuphezulu, amazinga e-ozone ayephansi kakhulu, engadluli ku-60 ppb.
Isibalo Esengeziwe S4 sibonisa amasimu kagesi alingisiwe ezimo ze-[-6.5 kV, 4.0 cm] kanye ne-[-3.8 kV, 0.5 cm], ngokulandelana. Amasimu ngokwezimo ze-[-6.5 kV, 4.0 cm] kanye ne-[-3.8 kV, 0.5 cm] abalwa njenge-2 × 105 V/m kanye ne-4.7 × 105 V/m, ngokulandelana. Lokhu kulindeleke, njengoba isilinganiso se-voltage nebanga siphezulu kakhulu esimweni sesibili.
Ku-fig. 3a, b ukhombisa ububanzi be-EWNS obulinganiswe nge-AFM8. Ububanzi obumaphakathi be-EWNS bezimo ze-[-6.5 kV, 4.0 cm] kanye ne-[-3.8 kV, 0.5 cm] babalwe njenge-27 nm kanye ne-19 nm, ngokulandelana. Ukuphambuka okujwayelekile kwe-geometric kokusatshalaliswa kwamacala [-6.5 kV, 4.0 cm] kanye ne-[-3.8 kV, 0.5 cm] kungu-1.41 kanye no-1.45, ngokulandelana, okubonisa ukusatshalaliswa kosayizi omncane. Kokubili ubukhulu obumaphakathi kanye nokuphambuka okujwayelekile kwe-geometric kusondele kakhulu ku-baseline-EWNS, okungu-25 nm kanye no-1.41, ngokulandelana. Ku-fig. 3c ukhombisa ukusatshalaliswa kosayizi we-baseline EWNS okulinganiswe kusetshenziswa indlela efanayo ngaphansi kwezimo ezifanayo.
Ku-Fig. 3d, e kukhombisa imiphumela yokuchayeka kweshaja. Idatha iyizilinganiso ezimaphakathi zokulinganisa okungu-30 ngesikhathi esisodwa kokuhlushwa (#/cm3) kanye nogesi (I). Ukuhlaziywa kukhombisa ukuthi ishaja elimaphakathi ku-EWNS lingu-22 ± 6 e- kanye no-44 ± 6 e- we- [-6.5 kV, 4.0 cm] kanye no- [-3.8 kV, 0.5 cm], ngokulandelana. Uma kuqhathaniswa ne-Baseline-EWNS (10 ± 2 e-), ishaja yabo engaphezulu iphakeme kakhulu, iphindwe kabili kunesimo se- [-6.5 kV, 4.0 cm] kanye nephindwe kane kune- [-3 .8 kV, 0.5 cm]. I-3f ikhombisa idatha yokukhokha eyisisekelo ye-EWNS.
Kusukela kumamephu okuhlushwa kwenombolo ye-EWNS (Izibalo Ezingeziwe S5 kanye ne-S6), kungabonakala ukuthi indawo [-6.5 kV, 4.0 cm] inenani elikhulu kakhulu lezinhlayiya kunendawo [-3.8 kV, 0.5 cm]. Kufanele futhi kuqashelwe ukuthi ukuhlushwa kwenombolo ye-EWNS kwaqashwa kuze kube amahora angu-4 (Izibalo Ezingeziwe S5 kanye ne-S6), lapho ukuzinza kwesizukulwane se-EWNS kwabonisa amazinga afanayo okuhlushwa kwenombolo yezinhlayiya kuzo zombili izimo.
Isithombe 3g sibonisa i-EPR spectrum ngemva kokukhipha ukulawula (ingemuva) kwe-EWNS elungiselelwe kahle ku-[-6.5 kV, 4.0 cm]. I-ROS spectrum nayo iqhathaniswa ne-baseline ye-EWNS ephepheni elishicilelwe ngaphambilini. Inani elibalwe le-EWNS elisabela nge-spin trap lingu-7.5 × 104 EWNS/s, elifana ne-Baseline-EWNS8 eshicilelwe ngaphambilini. I-EPR spectra ibonise ngokusobala ukuthi kukhona izinhlobo ezimbili ze-ROS, lapho i-O2- yayivame khona, kuyilapho i-OH• yayikhona ngenani elincane. Ngaphezu kwalokho, ukuqhathaniswa okuqondile kwamandla aphezulu kubonise ukuthi i-EWNS elungiselelwe yayinokuqukethwe kwe-ROS okuphezulu kakhulu uma kuqhathaniswa ne-baseline EWNS.
Ku-fig. 4 kukhombisa ukusebenza kahle kokufakwa kwe-EWNS ku-EPES. Idatha ifingqiwe futhi kuThebula I futhi iqhathaniswa nedatha yokuqala ye-EWNS. Kuzo zombili izimo ze-EUNS, ukufakwa kwakuseduze no-100% ngisho noma ku-voltage ephansi engu-3.0 kV. Ngokuvamile, i-3.0 kV yanele ukufeza ukufakwa okungu-100% kungakhathaliseki ukushintsha kweshaja ebusweni. Ngaphansi kwezimo ezifanayo, ukusebenza kahle kokufakwa kwe-Baseline-EWNS kwakungu-56% kuphela ngenxa yokushaja okuphansi (isilinganiso sama-electron ayi-10 nge-EWNS ngayinye).
Isibalo 5 kanye neThebula 2 sifingqa izinga lokungasebenzi kwama-microorganisms afakwe phezu kotamatisi ngemuva kokuchayeka ku-40,000 #/cm3 EWNS imizuzu engama-45 ngaphansi kwesimo esihle kakhulu [-6.5 kV, 4.0 cm]. I-E. coli kanye ne-L. innocua ezifakwe ku-incocua zibonise ukwehla okukhulu kwe-3.8 log ngemuva kwemizuzu engama-45 yokuchayeka. Ngaphansi kwezimo ezifanayo, i-S. enterica ibonise ukwehla okuphansi kwe-log kwezingodo ezingama-2.2, kuyilapho i-S. cerevisiae kanye ne-M. parafortuitum zibonise ukwehla kwe-1.0 log.
Ama-micrograph e-electron (Isithombe 6) abonisa izinguquko zomzimba ezibangelwa yi-EWNS kumaseli e-E. coli, i-Salmonella enterica, kanye ne-L. innocua okuholela ekungasebenzini. Amabhaktheriya okulawula abonise ama-membrane asele aphelele, kuyilapho amabhaktheriya avele ewonakele ama-membrane angaphandle.
Ukuthwebula izithombe ezincane ze-electron zokulawula kanye namabhaktheriya avele obala kwembule umonakalo we-membrane.
Idatha ngezakhiwo ze-physicochemical ze-EWNS ezilungiselelwe ndawonye ikhombisa ukuthi izakhiwo ze-EWNS (i-surface charge kanye nokuqukethwe kwe-ROS) zithuthuke kakhulu uma kuqhathaniswa nedatha eyisisekelo ye-EWNS eshicilelwe ngaphambilini8,9,10,11. Ngakolunye uhlangothi, usayizi wazo wahlala kububanzi be-nanometer, okufana kakhulu nemiphumela eshicilelwe ngaphambilini, okuvumela ukuthi zihlale emoyeni isikhathi eside. Ukusabalala okubonakalayo kungachazwa ngezinguquko ku-surface charge, ezinquma ubukhulu bomphumela we-Rayleigh, ukungahleliwe, kanye nokuhlangana okungenzeka kwe-EWNS. Kodwa-ke, njengoba kuchaziwe nguNielsen et al.22, i-surface charge ephezulu inciphisa ukuhwamuka ngokukhulisa ngempumelelo amandla/ukucindezelwa kwamanzi. Le mbono yaqinisekiswa ngokuhlola kuma-microdroplets22 kanye ne-EWNS encwadini yethu yangaphambilini8. Ukulahleka kwesikhathi esengeziwe kungathinta nosayizi futhi kufake isandla ekusatshalalisweni kosayizi okubonwe.
Ngaphezu kwalokho, ishaja ngesakhiwo ngasinye icishe ibe ngu-22–44 e-, kuye ngezimo, okuphakeme kakhulu uma kuqhathaniswa ne-EWNS eyisisekelo, eneshaja ejwayelekile yama-electron ayi-10 ± 2 ngesakhiwo ngasinye. Kodwa-ke, kufanele kuqashelwe ukuthi lena yishaja ejwayelekile ye-EWNS. Seto et al. Kuye kwaboniswa ukuthi ishaja ayifani futhi ilandela ukusatshalaliswa okujwayelekile kwe-log21. Uma kuqhathaniswa nomsebenzi wethu wangaphambilini, ukuphinda kabili ishaja ebusweni kuphinda kabili ukusebenza kahle kokufakwa ohlelweni lwe-EPES cishe kube ngu-100%11.